Remarks

A Map object is a container for map data. A Map object contains layers of both feature and graphic data.

The following is true for the ArcMap application model. Developers creating their own application may find some things different.

Every map document contains at least one Map object. Only one Map can have focus at a time and this Map is termed the focus map. A FocusMap property is conveniently placed on the IMxDocument interface. IMxDocument also has a Maps property which returns a reference (IMaps) to the entire collection of Maps. With IMaps you can get a create or delete Maps or get a reference to an existing Map.

All of the layers in a map share the same spatial reference. The Map's spatial reference is automatically set to the spatial reference of the first layer loaded. New layers loaded into a Map are projected to the Map's spatial reference if their spatial reference is different.

Map's are contained by MapFrames - the PageLayout object has a MapFrame and a MapFrame has a Map. Each Map, in turn, has a collection of Layers and MapSurrounds. Each MapSurround is also associated with a MapSurroundFrame. There are several types of Layers including FeatureLayers, FDOGraphicsLayers, and GroupLayers. MapSurrounds include Legends, NorthArrows, and ScaleBars.

Every Map has a Basic Graphics Layer where all graphics including labels are drawn by default. Users may create additional graphics layers called Groups or Annotation Target Layers all of which are managed by the CompositeGraphicsLayer.